Target tissue control of nerve fiber growth rate and periodicity in vitro.

Spinal cord and dorsal root ganglion nerve fibers of tadpoles elongate in vitro at an increased rate in the presence of target tissue or target-conditioned medium. These neurites extend in a cyclic fashion with the period between the occurrence of maximal growth rates being under target influence. Rate parameters may be an important feature in the understanding of directed nerve growth during development and regeneration.